to take back the white house. >> reporter: a new mood after many saw a new mitt romney last night. >> let's get back to medicare. the president said that the government can provide the service at lower cost and without a profit. >> reporter: in control, assertive, presidential. while barack obama kept his eyes and his energy low. >> it's very rare that stylistically there's such a clear triumph of one side over the other. >> reporter: a rally in denver, the president admitted he got surprised. >> when i got onto the stage, i met this very spirited fellow who claimed to be mitt romney. >> reporter: he charged romney changed his stance on taxes and spending. >> but if you want to be president, you owe the american people the truth. >> reporter: some felt mr. obama owed them a better debate. >> he looked like he was tired, drained. >> i think he didn't have the practice. >> you more worried obama might lose now? >> well, no, not really. >> reporter: obama strategists hint the boss learned a lesson. >> he'll review it and if he wants to make some changes in the next debate, he'll do so.